1. Field of the Invention
This invention relates to a method for producing biofuels, and more specifically this invention is related to utilizing naturally occurring biological pathways, both photosynthetic and non-photosynthetic, as a method for manufacturing biofuels.
2. Background of the Invention
Rising energy prices, supply uncertainties, and environmental concerns all threaten the security of the United States. Production of fuel from renewable energy sources, more particularly from agricultural sources, provides a way to enhance the nation's security. Also, the search continues for ways to produce biofuels without competing with land use for food, high-yield farmlands, or increasingly limited water resources.
Currently, ethanol is the primary biofuel, produced primarily from grain or sugar cane. There are significant development efforts to produce ethanol from cellulosic materials.
Biodiesel, produced by a transesterification of vegetable oil, is the second largest biofuel. Biodiesel is not an ideal fuel because its long chain length ester linkages affect combustion properties enough that it does not serve as a direct replacement for petroleum diesel. Biodiesel is primarily produced from edible oil seeds including soybeans, canola (rapeseed), or tropical oils such as palm. There are significant efforts to produce biodiesel from non-competitive oil seeds, including jatropha and pennycress.
Recently there has been significant research interest to produce biodiesel from aquatic species, primarily microalgae. Production of biodiesel from microalgae would address competition regarding land and resource use in comparison to edible oil seeds. Transition to algae-based biodiesel does not address the compatibilities issues regarding biodiesel.
Several factors have contributed to the lack of monumental breakthroughs in the biofuels field. Among them include the fact that teams are working to make fuels that directly mimic gasoline and diesel. For example, many investigators are employing chemical reduction of traditional triglycerides or fatty acids. These strategies require both chemical reactors and sources of hydrogen or other reducing molecules. With current technology, the hydrogen must be derived from fossil fuel or biomass gasification.
Production of fuel-like molecules in eukaryotes is challenging. Higher plants and algae are relatively complex organisms and so are genetic engineering efforts to manipulate them. In addition, higher plants and algae are less flexible in their ability to adapt and thrive in a variety of growth conditions and environments, and, hence, are more expensive to cultivate.
A need exists in the art for a method to produce fuel-like molecules from organisms with a minimum number of genetic modifications to the organisms. Any biofuel system and method for producing biofuel should not compete with food production resources, such as high-yield farmland.